Various types of intervertebral retention prostheses have previously been made, either rigid or flexible, the function of which is to eliminate lumbar vertebral frontal and sagittal rotatory instability. The rigid prostheses comprise plates, rods with hooks, and the flexible prostheses are formed by ligaments associated with rigid or flexible blocks.
However, these known ligamentary systems do not make it possible to stabilize flexion/extension and rotation in a satisfactory manner.